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knew themselves wiser, from the sympathy awakened by the glow of his lecture. Besides, no one could be indifferent to the moral example displayed by this, the first syndic, the chief of state, the possessor of a large patrimonial fortune, who was thus laborious in the discharge of a daily duty, without other motive than the love of science-for no other recompense than the respect accorded to noble and unselfish conduct. Those favorites of fortune who pass their days in the pursuit of idle pleasure, have no idea of the rational enjoyment to be derived from the pursuit of knowledge or the disinterested instruction of youth. Were an entire aristocracy similarly disposed, leading its followers through the learning of ancient times and the science of the present, what couquests would be made in the domains of intelligence; conquests which would necessitate no violation of right nor infliction of wrong, would bring loss or distress to none, but benefit to all.

During the long wars of the revolution and of the empire, Genera rendered great service to the scientific world by the publication of a review which her extended commercial relations and the cosmopolitan babits of her people supplied with abundant information upon all subjects, and which was edited by a distinguished physicist, M. Pictet, under the title Bibliotheque Britannique. It was by means of this periodical that the works of the English scientists became known over the continent; and through the personal influence of the eminent men who assisted in its compilation, it retained long after peace was established the monopoly of the earliest foreign intelligence. In its pages Arago, Tho was on a visit to Geneva, in 1820, first learned of the great discovery of Oersted, the action exerted by the electric current of the voltaic pile upon the magnetic needle. At that time it was known that two substances could act upou each other, combining and producing changes in their properties, exhibiting phenomena which constitute an essential part of chemistry, but no one had ever seen what was then called an imponderable fluid act upon aņother. Light produced no effect upon heat, and neither acted upon electricity. Oersted, however, announced that electricity could be made to act upon magnetism. A new science, with the most remarkable practical applications, of which the electric telegraplı is only one example, was developed from this fruitful germ. All who assisted in establishing the genuineness of this wonderful discovery were greatly impressed by it, and no one felt itfclined to contradict the grave comment of Pierre Prévost, the author of the theory of the unstable equilibrium of radiant hcat : Novus rerum nascitur ordo.

Arago, on his return to Paris, thus speaks of the event: “Professor De La Rive, of Geneva, who has himself discovered many curious phenomena with the powerful battery in his possession, allowed me to wit. ness his verification of the experiments of M. Oersted before MM. Prévost, Pictet, Th. de Saussure, Marcet, de Candolle, &c., and I was entirely convinced of the accuracy of the principal facts stated by the Danish philosopher.” I am, I believe, the sole survivor of this histor. ical scene, in which I took part as one of the et cætera of Arago, and I shall never forget the powerful impression produced upon those who were present. Nearly all came with the conviction that Oersted was the dupe of some illusion; but they saw the magnetic needle obey the action of the electric current, move in one direction when the conducting-wire of the battery was placed above it, and in the contrary direction when placed below it, and were convinced that these effects could be attributed to no external agitation, since they were produced in the vacuum of the air-pump, as well as in the open air, and ceased when a slip of wood was substituted for the magnetic needle.

Ampère, in Paris, entered upon the investigation of this phenomenon with great enthusiasm, and baving, by dint of earnest and persevering thought, arrived at general conceptions, he deduced from these inferences, which he immediately proceeded to verify by actual experiments, employing for the purpose all the resources of practical mechanics. The discoveries that followed week after week in rapid succession excited the unbounded admiration of Gaspard De La Rive, and no sooner had the Academy of Sciences of Paris announced some new inference of Ampère than the watch.making establishments of Geneva, under the direction of De La Rive, constructed the delicate apparatus conceived by the illustrious French physicist to verify his deductions, and varied the form so as to bring it within the means of the smallest laboratory.

If in this De La Rive was animated solely by a love of science, he was amply rewarded.

Auguste De La Rive, excited first by sympathy with his father, and afterward by individual interest in the new facts brought to light, determined to devote his life to the study of electricity. Born on the 9th of October, 1801, he was at the time of these researches a student in the university, but shortly after prepared resolutely and with success to compete for the chair of general physics left vacant by Pierre Prévost. Only twen. ty-one years of age, and aspiring to take the place of a professor well known throughout Europe, he was obliged to face a jury composed of sixty-six judges, that is to say, of all the professors of the academy, and all the mem. bers of the venerable company intrusted with the direction of the ecclesiastical affairs of Geneva. The academy was at that time a powerful corporation. Closely united with the church, it was considered the first educational establishment, and held control over all the other schools of the canton. It constituted a state within the state, and extended its jurisdiction even to politics and the affairs of the republic. The authority with which it was invested was founded upon traditional laws, and its functions were highly respected. Its professors, select men, were all capable of serious work and prolonged application. Very poorly remunerated for their services, their expenses far exceeded their emoluments, but they valued the prestige of a professorship, a trul: magisterial office, much more than its material profits. The hig! character of the political instruction attracted to the academy the rich

and noble families of the country, and the taste for letters and science it promoted, with the babit of devotion to their culture, was transmitted from generation to generation, enabling the school of Geneva to maintain a high position among the most renowned universities of Europe. It was a source of intellectual activity, and a center of light, such as is supported only by great effort in countries of much larger extent than Switzerland.

As soon as the discovery of Oersted was announced, Ampère offered the following explanation : The frictional electricity, or that developed by rubbing glass, long known, is a fluid in repose, and constitutes statical electricity. The electricity of the voltaic pile is this same fluid in motion in the direction of the axis of the conductors, and this is dynamical electricity. Again, this same fluid circulating around the molecules of a bar of iron or steel, in a plane perpendicular to the axis which united the two extremities, is magnetism. To give a material illustration of these forces, the water which moistens the surface of a solid body may represent statical electricity, the water which flows through an aqueduct dynamical electricity, and that which passes in the turns of an Archimedian screw, magnetism.

On the 4th of September, 1820, Arago announced to the French Academy the facts whose confirmation he had witnessed at Genera, and on the 25th of the same month Ampère read his valuable memoir, which alone would have given his name one of the highest places in the history of science. His theory of the principles of electro-magnetism was founded upon his fundamental experiment that two voltaic currents in the same direction attract each other, and, on the contrary, repel each other when they are in opposite directions—a phenomenon he bad fore. seen and predicted as a result of bis a priori conception. To this strik ing proof of the truth of his theory he soon added another. He imitated a magnet by passing a voltaic current through a metal wire' coiled into 3 spiral, and suspended freely in a vertical plane. This spiral was affected by the action of the earth like the magnetic needle, which Ampère explained by supposing that the lower parts of the wire, that is, those nearest the earth, controlled the whole. This experiment was also exhibited in its simplest form by suspending a rectangular wire so that it could move freely. When a voltaic current was passed through this, it arranged itself at right angles to the direction of the magnetic needle. Now Gaspard De La Rire removed the lower horizontal part, and the remainder of the wire was as much affected by the terrestrial influence as when the rectangle was complete.

The explanation of Ampère was thus shown to be incorrect, and his theory for a time lost its best support. His state of mind under the influence of this disappointment bordered on derangement. When alone, he passed hour after hour in profound meditation ; and when with his family, pursued the avocations of life in a sort of somnambulism, obliv. ious of everything around him. At length, however, in a moment of inspiration, the truth dawned upon him, and delivered him from this state of distraction. He caught sight of the proper solution of the problem, and in the experimental verification of this, Auguste De La Rive came to his aid, and by his ready invention reduced the phenomenon to its simplest elements. He removed one by one the sides of the rectangle, and reduced it at last to a single vertical wire, freely suspended, which, when the voltaic current passed through it, was as sensible to the action of the earth as the entire rectangle. These delicate experiments so interested Ampère that he came from Paris to Présinge, the country residence of De La Rive, to witness them, and to perfect the explanation to which he had given so much thought.

The memoir of the young physicist on the subject contains not only the new results he had obtained, but also the learned and decisive formula by which Ampère connected them with his theory, now com. plete and triumphant.

Thus in the very commencement of his career the name of Auguste De La Rive was associated with one of the most interesting episodes in the developmentofthe theory of Ampère, and his first investigations placed him at once in the focus to which all the intelligence of the age was directed. They not only brought him into relation with Ampère, but prepared the way for the life-long friendship which afterward united bim with Faraday, who already, grateful to his father for early recog. nition and encouragement under peculiar circumstances, was predisposed to regard him with favor. When Davy was making bis admirable investigations in regard to the voltaic battery, Great Britain and France were engaged in a desperate contest. The first class of the Institute, however, considering the field of science and the pursuit of truth above the prejudices occasioned by national quarrels, awarded to the English philosopher the prize offered in the department of electricity by Napoleon. Although the countries were then at open war, Davy shortly after received permission to visit Auvergne, in order to study the extinct volcanoes of that province, and was also allowed to go to Italy and continue bis researches on volcanoes in action. In this courteous exception, France set an example eminently worthy to be followed by all civilized nations. The passport Davy received included himself, his wife, and one servant. Faraday, eager to acquire knowledge, did not hesitate to accept the latter position. The young savant was unobserved in his new capacity while in Paris, as he did not speak a word of French, but it was quite otherwise at Présinge, where Davy remained some time. Gaspard De La Rive, observing his isolation, addressed some kind words to him during a hunting excursion. Discovering immediately that he was by no means an ordinary-servant, an explanation followed, and he was requested to take the place in the family, at the table of his host, which his true position and talent deserved. Davy, however, while he did not object to this arraugement when he was absent, iusisted that in his presence the subordinate position

assumed should be maintained. This simple incident might have made but little impression upon Faraday, had it not brought into strong contrast the pride of Davy and the affable cordiality of Gaspard De La Rire.

Even genius does not excuse pride or pardon exclusiveness. Davy, satiated with praise and loaded with honors, but lacking the sympathy of his countrymen, passed the last years of his life on the continent, and came to Geneva, to terminate sorrowfully, in a foreign country, his days of lassitude and ennui ; while, on the other band, when Faraday, endowed with the modesty which charms and the kindness which attracts, approached his end, the savants of the entire world evinced their affection for him; the most eminent personages of England testified their respect; his death was a source of universal regret, and his memory, cherished in all hearts, is still honored at the Royal Institution of London, in the amphitheater, the scene of his triumphs, by an annual and imposing ceremony presided over by the Prince of Wales. What a contrast is this !

As the scientific career of Gaspard De La Rive ended and that of his son commenced, a new era commenced, fraught with ideas to enlighten, agitate, and even trouble the world. The father had witnessed only the prelude to the great changes which were to take place, but welcomed with joy the new dawn. The son, after laboring with ardor and success in the unveiling of truth, at the close of his life contemplated, with sadness as well as pleasure, the unexpected consequences of the discoveries in which he had taken an active part.

A half a century ago science, although full of promise to those who sought to penetrate its mysteries, did not appeal to the common mind. Its language was little understood even by those who held the destinies of nations in their hands. Its demonstrations and discoveries were regarded by the public with a careless eye and considered of no impor. tance. Soon, however, under its influence, rapid vessels, impelled by steam, traversed the sea; railroads crossed the continents; thought circulated from one hemisphere to another through the electric telegraph ; the beet-root of the frozen regions rivaled the sugar-cane of the south; gas lighted the streets; fossil remains fertilized arid ground, and the colors from coal-oil vied with the fresh tints of the flowers; while the sail. ing-vessels lying idle in the ports, the forsaken stage-coach, the deserted roads, the laborer deprived of employment, were other but equally forci. ble witnesses to the irresistible power of the practical application of the principles which govern the universe. At the same time iron and steel were perfected and produced in abundance; powder and other fulminating substances were rendered manageable; rude and inefficient weapons of war were converted into large and powerful engines of destruction ; and in view of houses in ruins, crops destroyed, and the multiplied graves of the dead, it was impossible longer to question the

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